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Platelet AggregationPhase 4PARes-INCT01815008

Pharmacogenomics of Antiplatelet Response - I

A Phase 4 study testing Clopidogrel and Aspirin in people with Platelet Aggregation and Platelet Transcriptome, run by Johns Hopkins University at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This clinical trial is examining the role of genetic polymorphism on the effect of clopidogrel (with or without aspirin) on platelet response in persons at high-risk for myocardial infarction or stroke due to family history of early-onset coronary artery disease. Read more about this study

Who is it for?
Ages 45 to 75 years
What is being tested?
Clopidogrel and Aspirin
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
19 participants
Where
1 siteUnited States
Study dates
Oct 2012to Jun 2014
Phase
Phase 4
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 45 to 75 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Participants from the GeneSTAR cohort
  • Unaffected with no overt coronary artery disease or serious vascular event (stroke or peripheral vascular disease diagnosis
  • Presence of an occult coronary artery disease phenotype as defined by coronary artery calcium scores about the MESA (Multiethnic Study of Atherosclerosis) 75th percentile for age sex, and race or ≥ 1 stenoses in any of the major coronary arteries or main branches of > 50%, or coronary plaque volumetric scores above our own 75th percentile, or any combination on cardiac computed tomographic angiography (performed recently as part of the GeneSTAR study and present for all persons being recruited)/
  • Presence of occult cerebrovascular disease defined as presence of white matter hyperintensities (WMH) thought to represent ischemic small vessel cerebrovascular disease, and /or the presence of lacunes (old small strokes), or the presence of an Atherosclerosis Risk in Communities Study (ARIC) silent stroke score on a visual analogue scales of 4 or more (on a scale of 0-9).
  • Women who are postmenopausal.
  • Women who use a reliable contraceptive method; a reliable contraceptive method will be defined as personal history of tubal ligation, ongoing use of intra-uterine device, or ongoing use of oral contraceptive pills.

Who cannot join

  • Presence of any CAD or stroke, transient ischemic attacks, peripheral arterial disease
  • Persons taking aspirin, NSAIDS, or any anti-coagulants who are medically unable to stop them for a two week pre-trial
  • A history of allergy to aspirin or clopidogrel
  • Weight < 60kg
  • Age < 45 and > 75 years of age
  • A history of recent or any active bleeding
Show all 12Show fewer
  • Serious or current co-morbidity (AIDS, cancer)
  • Pregnant women as determined by urine dipstick pregnancy test
  • Any aneurysms on cranial magnetic resonance imaging/magnetic resonance angiography (obtained recently in the GeneSTAR participants)
  • Blood pressure above >=159/95mmHg
  • History of a gastric or duodenal ulcer, or significant gastrointestinal disease, like regional enteritis
  • Mental incompetence to make a decision to participate (developmentally disabled, and persons with diagnosed psychiatric disorders-documented in primary care records).

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Johns Hopkins University School of Medicine

    Baltimore, Maryland, 21287

Other trials in United States

About this study

Official title: PHARMACOGENOMICS OF ANTI-PLATELET RESPONSE - I

This clinical trial is examining the role of genetic polymorphism on the effect of clopidogrel (with or without aspirin) on platelet response in persons at high-risk for myocardial infarction or stroke due to family history of early-onset coronary artery disease.

Read the detailed description

The main goal of this study is to explore the impact of the PEAR1 genetic variant (rs12041331) on responsiveness to clopidogrel. The investigators will further assess the role of other genetic variants in determining the response to single or dual anti-platelet therapy. Apparently healthy subjects (N= 2108) from high-risk families are being (a) identified from a proband with early-onset CAD and (b) genotyped on the Illumina 1 million platform, with imputation to 2.5 million single nucleotide polymorphisms. The investigators plan to characterize the variance in platelet aggregation to multiple agonists (ADP, collagen, and arachidonic acid) after 1-week therapy with clopidogrel in a high-risk subset of GeneSTAR subjects (N=100). The investigators further plan to determine the extent to which variants identified in the PEAR1 gene modify platelet responsiveness to inhibition by clopidogrel in this high-risk subset. In addition, the investigators aim is to determine the extent to which variants in other recently discovered genes, by themselves, and in combination with PEAR1, modify platelet responsiveness to clopidogrel alone and with aspirin in this high-risk subset. Lastly, the investigators also want to determine what changes in platelet mRNA are produced by aspirin alone and by aspirin with clopidogrel.

Being tested
Clopidogrel, Aspirin
Keywords
Platelet aggregation, Clopidogrel, Platelet transcriptome
Medical subject headings
Coronary Artery Disease

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT01815008
Study groupRoleWhat they receive
ClopidogrelExperimentalClopidogrel 75 mg daily by mouth for 1 week then Clopidogrel 75 mg daily with aspirin 81 mg daily
Receives: Drug: Clopidogrel; Drug: Aspirin

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Difference in ADP-induced Platelet Aggregation

    ADP-induced platelet aggregation will be measured using impedance aggregometry in whole blood before and after 1-week of clopidogrel. The difference between the baseline and after clopidogrel therapy will be determined. Higher impedance represent higher platelet aggregation.

    Measured: at baseline and at 1 week

Secondary outcomes (3)
  1. Difference in Arachidonic Acid-induced Platelet Aggregation

    Arachidonic Acid-induced platelet aggregation will be measured using impedance aggregometry in whole blood before and after 1-week of clopidogrel. The difference between the baseline and after clopidogrel therapy will be determined

    Measured: At baseline and after 1-week

  2. Difference in Collagen-induced Platelet Aggregation

    Collagen-induced platelet aggregation will be measured using impedance aggregometry in whole blood before and after 1-week of clopidogrel. The difference between the baseline and after clopidogrel therapy will be determined

    Measured: At Baseline and at 1 week

  3. Changes in Platelet Transcriptome With Clopidogrel

    Platelet transcriptome will be examined before and after 1 week of therapy with clopidogrel and differences will be determined

    Measured: At baseline and at 1 week

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Mar 2013 (estimated)
  2. Study startOct 2012
  3. Primary completionJun 2014
  4. Study completionJun 2014

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 4
Primary purpose
Prevention
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
19 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01815008
Sponsor's protocol ID
K23HL105897-PARes-I
Other IDs
K23HL105897
Acronym
PARes-I
Status last verified
Nov 2016
First submitted
18 Mar 2013
Last updated
9 Jan 2017
Data monitoring committee
Yes

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Clopidogrel and Aspirin in people with Platelet Aggregation and Platelet Transcriptome, run by Johns Hopkins University at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 9 Jan 2017. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 9 Jan 2017). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Difference in ADP-induced Platelet Aggregation (time frame: at baseline and at 1 week). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Jan 2017.

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